JP2910613B2 - Matte electrodeposition paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matte electrodeposition paint suitable for applying a matte coating film to metal products and metal parts such as aluminum sashes and steel furniture.

[0002]

2. Description of the Related Art Electrodeposition coating uses water as a solvent, so there is no danger of fire, explosion, etc., and it is possible to apply a large amount of continuous coating over a long period by automating the process. Further, it has many advantages such as easy control of the coating thickness, and has been widely used in the past.
Among electrodeposition coatings, matte electrodeposition coating can obtain a coating film with reduced metallic luster, and as a means of improving not only the surface protection of various metal products, but also the appearance, Is spreading

[0003] Several matte electrodeposition coating methods have been proposed so far, and the following methods are typical. Prior art 1: A method in which an inorganic transparent pigment having a matting effect is contained in an electrodeposition paint bath, and the inorganic pigment is precipitated together with an organic resin component of the paint at the time of electrodeposition coating, and irregularly reflected on the surface of the inorganic pigment. Prior art 2: a method in which an electrodeposited object is immersed in an acid or an organic solvent or the like before baking and curing to etch the coating surface to form fine undulations and irregularly reflect the coating surface. . Prior Art 3: Two or more of those that do not dissolve in each other, do not crosslink and polymerize each other, or have different curing rates, such as polyethylene wax, polycarbonate resin, polyethylene particles, and resins having different glass transition points. A method in which a paint containing a resin is electrodeposited, and unevenness is formed on the surface of the coating film by hardening strain generated during baking, thereby causing irregular reflection. Prior Art 4: Instead of an inorganic pigment, a paint contains gel particles chemically bonded to a base resin, and further, undulations are formed on the coating film surface due to a difference in shrinkage between the base resin and the gel particles during baking. And irregular reflection on the surface of the coating film surface and the inner gel particle surface.

However, in the above prior art,
There are the following problems, and improvement is desired. 1． Sedimentation of particles: In the above-mentioned prior arts 1, 3, and 4, since the specific gravity differs between the particles contained in the paint and the base resin, the particles settle during storage of the paint or during the painting process. Alternatively, the particles are separated to form a coating film in which the particles are unevenly dispersed. 2． Gloss unevenness: In the above-mentioned prior art 2, prior art 3 and prior art 4, since the surface condition of the obtained coating film is different due to a slight difference in the treatment condition with an acid or an organic solvent or the coating condition, Often uneven gloss is produced. 3． Deterioration of coating properties: In the above-mentioned conventional technology 2 and conventional technology 3, there is a problem that the coating film is peeled off due to partial excessive etching, the weather resistance is deteriorated, or the inside of the coating film is deteriorated. Since considerably large hardening marks remain, the adhesion of the coating to the object to be coated is weak, and various properties such as hardness, acid resistance, alkali resistance, weather resistance, and heat and cold cycle resistance of the coating after the electrodeposition coating are reduced. There is a problem of doing.

[0005] As a matte electrodeposition coating for solving the above-mentioned problems, prior art 5: an electrodeposition coating coating in which a metal organic salt such as an aluminum complex compound is mixed with an electrodeposition coating containing a specific amount of water. A composition has been proposed (JP-A-58-452).
70).

However, in the above-mentioned electrodeposition coating composition, when a metal organic salt is added to the electrodeposition coating composition, a functional group such as -OH group or -COOH group of the acrylic polymer reacts with the metal organic salt. The coating bath cannot be used as a coating bath because the coating bath thickens or gels with the passage of time, and in some cases, agglomeration or settling of particles occurs. The resulting coating film has a problem in that the liquid stability is poor, such as a decrease in the smoothness and a bumpy coated surface. Furthermore, metal organic salts such as aluminum complex compounds have the problem that paints and coatings turn yellow.

An aluminum alcoholate in which the alcoholate group is a relatively short-chain alkoxide group and does not contain a complex generally has a high reactivity with water and a carboxyl group in an acrylic polymer, and is a coating material containing a carboxyl group. When blended in a system, the paint tends to thicken or gel, and cannot be used particularly for making a water-based paint.

[0008]

SUMMARY OF THE INVENTION The present inventors have solved the above problems 1 (sedimentation of particles), 2 (uneven gloss) and 3 (decrease in weather resistance etc. of a coating film). We are keen to provide an excellent matte electrodeposition paint that does not cause thickening or gelling of the paint bath during manufacture, is easy to manufacture, can be applied stably, and has no coloring such as yellowing of the paint and coating film. As a result of research, the present invention has been completed.

[0009]

DISCLOSURE OF THE INVENTION The present invention relates to an acrylic polymer, a water-miscible organic solvent in which the polymer is soluble (hereinafter referred to as a water-miscible organic solvent), and aluminum represented by the formula (1). It is a water-soluble or water-dispersible matte electrodeposition paint composed of an alcoholate, an amino resin, an alkaline substance and water.

[0010]

Embedded image Al (OR ¹ ) _m (OR ² ) _3-m (1) (where R ¹ represents an alkyl group or alkenyl group having 5 to 36 carbon atoms, or an aryl group, and R ¹ is the same or different. R ² represents an alkyl group having 4 or less carbon atoms, and R ² may be the same or different.
≦ m ≦ 3. )

Hereinafter, various components constituting the matte electrodeposition paint of the present invention, preparation of an electrodeposition paint bath, and an electrodeposition coating method will be described in detail. In this specification, “(meth) acrylate” means acrylate and / or methacrylate.

Acrylic Polymer The acrylic polymer used in the present invention preferably contains a carboxyl group in the main chain or side chain of the acrylic polymer. One or two of vinyl polymerizable α, β-unsaturated fatty acids such as methacrylic acid, maleic acid, maleic anhydride, fumaric acid, maleic acid monoester, itaconic acid, itaconic acid monoester, crotonic acid, citraconic acid, etc. A method of polymerizing more than one kind is appropriate, and it is preferable to use acrylic acid and methacrylic acid in combination in order to impart a good matting property to the coating film.

The acrylic polymer preferably has a hydroxyl group introduced therein in order to increase the reactivity with an amino resin and an aluminum alcoholate described below, in addition to the carboxyl group. As a method for introducing a hydroxyl group into an acrylic polymer, one or more kinds of hydroxyl group-containing monomers such as β-hydroxyethyl (meth) acrylate, β-hydroxypropyl (meth) acrylate or allyl alcohol are polymerized. The method is general.

The acrylic polymer further contains methyl (meth) acrylate and ethyl (meth) acrylate as acrylic components.
(Meth) such as acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, normal butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate and lauryl (meth) acrylate, and glycidyl (meth) acrylate ) Acrylate or one or more of (meth) acrylamides such as N-butoxy (meth) acrylamide and N-methylol (meth) acrylamide can be copolymerized, and the above (meth) acrylate and (meth) acrylamide can be copolymerized. Besides, styrene,
α-Methylstyrene, vinyl acetate, vinyl propionate, vinyl chloride, vinylidene chloride, (meth) acrylonitrile, vinyl fluoride, vinylidene fluoride and the like may be copolymerized.

The acrylic polymer having a carboxyl group contains a sufficient amount of a carboxyl group for the polymer to obtain water dilutability, that is, a carboxyl group having an acid value of about 20 to 120 KOH mg / g. It is usually desirable that the hydroxyl-containing monomer is copolymerized in the acrylic polymer in an amount of about 40 to 200 KOH mg / g in terms of the reactivity with the amino resin and aluminum alcoholate. It is usually desirable.

The acrylic polymer can be produced by any of known methods such as solution polymerization, emulsion polymerization, suspension polymerization and the like, but various solvents such as methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, trimethylolpropane and the like. And propylene glycol-based solvents such as propylene glycol monomethyl ether and propylene glycol mono-t-butyl ether; carbitol-based solvents; glyme-based solvents; cellosolve acetate-based solvents; and aromatics such as benzyl alcohol and phenethyl alcohol. Solution polymerization using one or more water-miscible solvents such as alcohols in combination is a desirable production method. When an acrylic polymer is produced by a method including water such as emulsion polymerization and suspension polymerization,
After removing water, it is necessary to dissolve in the above-mentioned solvent to make it anhydrous.

As the polymerization catalyst, an azo compound, a peroxide compound, a sulfide compound, a sulfine compound, a diazo compound, a nitroso compound, or the like can be used in a usual amount.

The acrylic polymer preferably has a weight average molecular weight in the range of 7,000 to 150,000, more preferably 10,000 to 130,000, and has a viscosity of 100,000 cps or less at room temperature. However, those having a relatively high molecular weight are preferred.

The acrylic polymer solution obtained by the above method can be diluted with the following water-miscible organic solvent, if necessary, to facilitate preparation of a coating bath. The preferred mixing ratio of the water-miscible organic solvent and the acrylic polymer in the paint of the present invention is 40 to 70% by weight of the acrylic polymer and 60 to 30% by weight of the water-miscible organic solvent.

Water-miscible organic solvent As the water-miscible organic solvent in the present invention, various organic solvents having water miscibility are used. When the above-mentioned acrylic polymer is produced by solution polymerization, Water-miscible organic solvents used, for example, methanol solvents, alcohol solvents such as ethanol, isopropanol, ethylene glycol, propylene glycol, trimethylolpropane and glycerin, and propylene glycol solvents such as propylene glycol monomethyl ether and propylene glycol mono-t-butyl ether It is preferable to use one or more of a solvent, a carbitol-based solvent, a glyme-based solvent, a cellosolve acetate-based solvent, and an aromatic alcohol such as benzyl alcohol and phenethyl alcohol.

Amino resin The amino resin in the present invention is a condensate of an amino compound such as melamine, urea or benzoguanamine and an aldehyde compound such as formaldehyde or acetaldehyde, or the condensate is further treated with methanol, ethanol, isopropanol, n- A condensate modified with an alcohol such as butanol, which is relatively hydrophobic, is desirable, but is usually methanol, ethanol, isopropanol, methyl cellosolve, ethyl cellosolve, n-butyl cellosolve, ethylene glycol, propylene glycol, It is used as a solution in a water-miscible solvent such as methylolpropane or glycerin.

Particularly preferred amino resins are alcohol-modified melamine-formaldehyde condensates, in particular, the sum of imino groups and methylol groups in the condensates is not more than 2 per one triazine ring of melamine, and the remainder is entirely alcohol. Alkyl etherified ones, more preferably the alkyl group in the alkyl ether is a lower alkyl having 4 or less carbon atoms such as methyl, ethyl, isopropyl, n-propyl, n-butyl, isobutyl, tert-isobutyl and the like. And one or more mixed alkyl groups selected from the above groups.
Examples of commercially available products include Cymel 232 and Cymel 235 (manufactured by Mitsui Cyanamid Co., Ltd.).

The preferred mixing ratio of the acrylic polymer and the amino resin is from 9: 1 to 4: 6 as a weight ratio of the resin, but the content of the functional group in the acrylic polymer and the desired coating The mixing ratio can be changed according to the film performance and the like.

(A) Aluminum alcoholate The aluminum alcoholate in the present invention is represented by the formula (1)
It is as represented by. In the present invention, the aluminum alcoholate is not only a single compound but also (O)
Mixtures of compounds differing in the type or ratio of the (R ¹ ) and (OR ² ) groups can also be used, and thus, m in formula (1) and in the same formula is the average chemical formula and value in the mixture. .

[0025]

Embedded image Al (OR ¹ ) _m (OR ² ) _3-m (1) (where R ¹ represents an alkyl group or alkenyl group having 5 to 36 carbon atoms or an aryl group, and R ¹ is the same or different. R ² represents an alkyl group having 4 or less carbon atoms, and R ² may be the same or different.
≦ m ≦ 3. )

An alkyl or alkenyl group in which R ¹ has less than 5 carbon atoms increases the reactivity of the aluminum alcoholate and causes the paint to thicken or gel. In the case of an alkyl group or an alkenyl group having more than 36 carbon atoms, the viscosity of the aluminum alcoholate becomes high, it is easily crystallized at room temperature, and it is difficult to handle it, for example, because it needs to be heated or dissolved in various solvents. R ¹ preferably has 15 to 15 carbon atoms.
27 alkyl groups or alkenyl groups, or aryl groups.

Specific examples of the alkyl group or alkenyl group having 5 to 36 carbon atoms (hereinafter also referred to as long chain) in R ¹ include hexyl, lauryl, 2-ethylhexyl, 2-hexyldecyl, and A straight-chain or branched alkyl group such as -decyltetradecyl group, or an alkenyl group such as oleyl group, and more preferably a 2-hexyldecyl group, and a 2-decyltetradecyl group or oleyl group. .

There is no particular limitation on the number of carbon atoms in the aryl group in R ¹ , but preferred specific examples include a benzyl group and a phenethyl group, with a benzyl group being more preferred.

R ¹ may be the same or different.

In R ² , specific examples of the alkyl group having less than 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and s.
ec-butyl and tert-butyl groups;
An isopropyl group is preferred. R ² may be the same or different.

In the formula (1), when m <1, the reactivity of the aluminum alcoholate is high, and the viscosity and gelation of the coating film are caused. When m> 2.4, the reactivity is mild, but it tends to crystallize at room temperature, requires handling such as heating or dissolving in various solvents, and may have a poor matting effect. From a certain point, preferably, 1 ≦ m ≦ 2.4.

Specific examples of the aluminum alcoholate of the formula (1) include isopropoxyaluminum hexylate, isopropoxyaluminum-2-ethylhexylate, isopropoxyaluminum-2-hexyldecylate, and isopropoxyaluminum-2-yl. It has a long-chain linear or branched alkyl or alkenyl group such as decyltetradecylate, isopropoxyaluminum laurate, or isopropoxyaluminum oleyl, and the average number of moles of the long-chain alkyl or alkenyl group Is an aluminum alcoholate having an aryl group such as isopropoxyaluminum benzylate, isopropoxyaluminum phenethylate and the average number of moles of the aryl group is 1 to 3 And the like.

Specific examples of particularly preferred aluminum alcoholates include an aluminum alcoholate having an alkyl group, an alkenyl group, or an aryl group having 15 to 27 carbon atoms and having an average mole number of 1 to 2.4. For example, an aluminum alcoholate having an alkyl group or an alkenyl group such as isopropoxyaluminum-2-hexyldecylate, isopropoxyaluminum-2-decyltetradecylate, isopropoxyaluminum oleate, or an aryl such as isopropoxyaluminum benzylate Aluminum alcoholate having a group is exemplified.

In the present invention, the mixing ratio of the aluminum alcoholate is based on 100 parts by weight of the total amount of the resin solid consisting of the acrylic polymer and the amino resin (hereinafter, “parts” means parts by weight). 0.1 to 15 parts, more preferably 0.5 to 10 parts, the larger the molecular weight of the acrylic polymer, or the larger the acid value or hydroxyl value of the acrylic polymer, the smaller the amount of the compound is sufficient. A matting effect tends to be obtained.

The aluminum alcoholate of the formula (1) is
The usual aluminum alcoholate production conditions can be used, and for example, it can be produced as follows. The raw material aluminum alcoholate is Al (O
R ² ) ₃ , for example, while stirring aluminum isopropoxide, into it an alcohol of the formula R ¹ OH,
For example, 1.0 mol to 3.5 mol of 2-hexyldecanol is added dropwise to 1 mol of the starting aluminum alcoholate such that the number of mols of the (OR ¹ ) group in the target aluminum alcoholate is m (1 to 3 mol). And gradually heated to distill off alcohol as a by-product.

○ Alkaline substance The water-soluble or water-dispersible property in the present invention is provided by adding an alkaline substance. That is, for example, usually 0.2 to 1.0 with respect to the carboxyl group of the acrylic polymer.
Equivalent alkaline substances, for example, monoethylamine, diethylamine, aliphatic amines such as triethylamine, dimethylethanolamine, diethanolamine, alkanolamines such as triethanolamine, pyridine,
By neutralizing the acrylic polymer using a cyclic amine such as piperidine or other organic bases or an inorganic base such as ammonia, caustic soda, caustic potash, etc., water solubility or water dilutability can be imparted.

Method for producing electrodeposition paint The electrodeposition paint of the present invention is produced by an acrylic polymer, a water-miscible organic solvent, an aluminum alcoholate, an amino resin,
It can be produced by appropriately mixing an alkaline substance and water. As a preferred production example, a mixture in which an acrylic polymer is dissolved in a water-miscible organic solvent, an aluminum alcoholate, an amino resin, and an alkaline substance are appropriately mixed, and then water is gradually added with stirring to obtain a water-soluble or aqueous dispersion. It can be obtained by making it sex.

A more preferable method is to mix an aluminum alcoholate and an amino resin sufficiently in advance, and then mix this with a mixture obtained by dissolving an acrylic polymer in a water-miscible organic solvent to prepare an anhydrous mixture. , An alkaline substance, and water is gradually added thereto while stirring to make the substance water-soluble or water-dispersible. At this time, there is no particular limitation on the timing of addition of the alkaline substance and the substance to be added, but it is preferable that the acrylic polymer is added by a method that easily becomes water-soluble or water-dispersible. Further, the above-mentioned water-miscible organic solvent may be further added later, if necessary. The mixing temperature of each component is also not particularly limited, but the preferred temperature range is 5 to 5.
95 ° C.

In the production of the electrodeposition coating composition of the present invention, the viscosity increase or gelation of the coating composition is extremely slow, and there is an advantage that a stable coating composition can be easily produced. In some cases, the paint thickens over time and becomes difficult to stir, but when water is slowly added in the presence of an alkaline substance, surprisingly, it becomes water-soluble or water-dispersible without residues. Paint production is easy.

The electrodeposition paint of the present invention can be used as a matte electrodeposition paint as it is, or blended with or diluted with a desired additive. become that way. A water-miscible organic solvent such as isopropyl alcohol or the like is used to add 280 parts of a mixture (1) of an acrylic polymer whose resin solid content is adjusted to 50% by weight, and 1 to 15 parts of an alkaline substance such as triethylamine. Stir for 1 hour. On the other hand, 60 parts of amino resin and 5 parts of aluminum alcoholate or 10 parts
A water-miscible organic solvent such as isopropyl alcohol up to 0 parts was added in advance, and the mixture was mixed and stirred at room temperature for 1 hour.
Prepare mixture (2). Thereafter, this is added to the above mixture (1) and stirred at room temperature for 1 hour. At this time, the viscosity may slightly increase, but if necessary, the viscosity may be reduced by diluting with a small amount of a water-miscible organic solvent such as isopropyl alcohol. While stirring the thus obtained mixture (3), water is gradually added to produce a water-soluble or water-dispersible mixture (4), that is, a matte electrodeposition coating composition. The above mixture may be gradually added to water, or an alkaline substance may be added as necessary. If the mixture (4) contains an excessive amount of an organic solvent, the electrodeposition properties are affected. Therefore, the solvent may be distilled off under reduced pressure while heating the mixture (4) containing water.

The solid concentration of the electrodeposition coating bath is suitably from 5 to 20% by weight, and if it is less than 5% by weight, the coating voltage may increase. If it exceeds 20% by weight, loss outside the coating system may occur. It is not economical because it can grow. Further, if necessary, a dye, a colorant, and various other commonly used additives may be added to the paint obtained by the present invention.

Electrodeposition method Electrodeposition is carried out under the conditions usually employed, for example, at a temperature of a coating bath of 15 to 35 ° C., a coating voltage of 50 to 250 V, and a processing time of 1 to 5 minutes. It can be carried out. After removing the paint adhered on the surface of the electrodeposition coating film deposited by the electrodeposition coating by washing with water and exposing the surface of the electrodeposition coating film, 100 to 25
The coating is baked at a temperature of 0 ° C, more preferably 150 to 200 ° C.

The object to be applied to the matte electrodeposition coating is not particularly limited as long as it has conductivity. However, when a so-called alumite-treated material obtained by anodizing aluminum or an aluminum alloy is used, it is difficult to obtain smoothness. This is particularly preferable because a uniform matte coating film having excellent performance such as the above can be obtained.

[0044]

The present invention will be described more specifically with reference to the following reference examples, examples and comparative examples.

REFERENCE EXAMPLE 1 (Synthesis of Acrylic Polymer) A four-necked flask was equipped with a stirrer, a thermometer, a cooler, and a dropping funnel.
22 g was charged and heated to 80 ° C. while stirring. Separately, 270 g of methyl methacrylate, 100 g of styrene, 200 g of isobutyl acrylate, 300 g of β-hydroxyethyl acrylate, 40 g of methacrylic acid, 60 g of acrylic acid, and 30 g of N-butoxyacrylamide were mixed, and the mixture was added dropwise to the polymerization catalyst azobisisobutyro. It was added dropwise over 7 hours together with 18 g of nitrile.
Thereafter, 3 g of azoisobutyronitrile was further added and aged to obtain an acrylic polymer 15 having a carboxyl group.
38 g were obtained. Solid content 65%, viscosity 330ps (30
° C). The characteristics of the obtained acrylic polymer were as follows. Acid value: 73 KOHmg / g solid Hydroxyl value: 145 KOHmg / g solid Weight average molecular weight: 28,000

Reference Example 2 (Synthesis of Aluminum Alcoholate) A four-necked flask was equipped with a stirrer, a thermometer, a cooler, and a dropping funnel, and aluminum isopropoxide [manufactured by Kawaken Fine Chemical Co., Ltd.] was placed in the flask. ] 204 g (1 mol). Hexyl alcohol 20 from the dropping funnel
4 g (2 mol) was added dropwise at room temperature with stirring. After dropping,
The isopropyl alcohol generated by gradually heating was distilled off. After the temperature of the solution reached 110 ° C., the pressure inside the system was reduced and the system was heated (125 ° C.) until the isopropyl alcohol was no longer distilled off. Then, it was cooled and isopropoxy aluminum hexylate (hexylate) as a pale yellow viscous liquid was obtained. 87.4 g (99.8%) of an average number of moles 2) was obtained. H-N
The MR was measured to confirm that the product was the target.

Reference Examples 3 to 13 (Synthesis of Aluminum Alcoholate) Various aluminum alcoholates were synthesized in the same manner as in Reference Example 2 except that the alcohol to be reacted was changed as shown in Table 1 below.

Example 1 60 parts of the acrylic polymer obtained in Reference Example 1 was diluted with a water-miscible solvent of isopropyl alcohol to reduce the resin solid content to 50 parts.
Adjusted to% by weight. Triethylamine having a degree of neutralization of 65% with respect to the acid component of the acrylic polymer is blended,
Stirred at room temperature for 1 hour. On the other hand, as an amino resin, 40 parts of Cymel 232 (manufactured by Mitsui Cyanamid Co., Ltd.) and 3 parts of the aluminum alcoholate obtained in Reference Example 2 were previously mixed and added, followed by mixing and stirring at room temperature for 1 hour. Thereafter, the mixture was added to the mixture of the water-miscible organic solvent and the acrylic polymer, followed by stirring at room temperature for 1 hour. The mixture thus obtained was easily emulsified and dispersed by gradually adding deionized water while stirring. It was diluted to a solid content of 8% and filtered through a 400-mesh wire net to prepare an electrodeposition coating composition.

Next, the electrodeposition coating composition was electrodeposited on a black-colored alumite-treated material at 22 ° C. for 3 minutes. After the electrodeposition coating, the coating film obtained by baking was measured for film thickness and gloss. Further, the state of the bath after the storage stability test for one month was carried out while the coating material was kept at 35 ° C., and the appearance of the coating film after the electrodeposition coating and baking again was evaluated. The results are shown in Table 2 below.

The following procedures were used to measure the characteristics of various coating films. Film thickness: Measured with an eddy current type thickness meter according to JIS-H-8680-3.2. Gloss: Specular gloss of 60 ° was measured according to JIS-Z-8741. Appearance of coating film: The presence or absence of appearance abnormality such as unevenness or blister (bubble) and the presence or absence of yellowing were visually determined. Bath liquid appearance: The color of the liquid and the state of sedimentation or separation were visually determined.

Examples 2 to 11 Electrodeposition coating baths were prepared and electrodeposited in the same manner as in Example 1 except that the various aluminum alcoholates described in Reference Examples 3 to 13 were used. The coating conditions, various properties of the coating film, and the storage stability of the electrodeposition coating bath are shown in Table 2 below.

Comparative Example 1 An electrodeposition coating bath was prepared in the same manner as in Example 1 except that aluminum alcoholate was not used, and the electrodeposition coating bath was used for electrodeposition coating. Various properties of the obtained paint and coating film are shown in Table 3 below. The resulting coating film had high gloss and did not become a matte coating film.

Comparative Example 2 An electrodeposition coating bath was prepared in the same manner as in Example 1 except that monosec-butoxyaluminum diisopropylate (manufactured by Kawaken Fine Chemicals Co., Ltd.) was used as the aluminum alcoholate. As a result, immediately after mixing the acrylic polymer and monosec-butoxyaluminum diisopropylate, the mixture became thick and could not be stirred. When deionized water was added little by little and the mixture was forcibly mixed, a coating was obtained by dissolving or dispersing to a certain extent, and electrodeposition coating was performed. Various properties of the obtained paint and coating film are shown in Table 3 below. Many bumps were seen on the coating film, and the coating was rough and not in a state that could withstand the coating.

Comparative Example 3 An aluminum alcoholate complex compound, aluminum chelate D (containing no alkoxy group) [containing no alkoxy group] (manufactured by Kawaken Fine Chemical Co., Ltd.) was used in place of 3 parts of the aluminum alcoholate obtained in Reference Example 2. In the same manner as in Example 1, an electrodeposition coating bath was prepared. Various properties of the obtained paint and coating film are shown in Table 3 below. Although the initial state of the coating film was relatively good, although the appearance of the coating film was slightly uneven, the electrodeposition coating bath after one month at 35 ° C. turned yellow and sedimentation was observed. The coating film was rough, and yellowing was also observed.

Comparative Example 4 Aluminum alcoholate complex compound A [Al (CH ₃ H ₇₎
O) (C ₂₄ H ₄₉ O) (ethyl acetoacetate)] was used in the same manner as in Comparative Example 3 for electrodeposition coating. Various properties of the obtained paint and coating film are shown in Table 3 below. Although the initial state of the coating film was good in appearance, the electrodeposition coating bath after one month at 35 ° C. was yellow.

(Comparative Example 5) HYTEC E4A (polyethylene wax emulsion manufactured by Toho Chemical Co., Ltd.) was added to the electrodeposition coating bath of Comparative Example 1 (solid content: 100 parts) as a solid content of 15%.
A partly added electrodeposition coating bath was prepared and subjected to electrodeposition coating. Various properties of the obtained paint and coating film are shown in Table 3 below. The electrodeposition paint bath separated into two phases even at the stage where it was allowed to stand at 35 ° C. for one day.

[0057]

[Table 1]

[0058]

[Table 2]

[0059]

[Table 3]

[0060]

EFFECTS OF THE INVENTION The matte electrodeposition paint of the present invention eliminates sedimentation of particles, unevenness of gloss, deterioration of weather resistance of a coating film, etc., and does not cause thickening or gelling of the paint bath during the production of the paint bath. It is easy to manufacture and therefore can be applied stably. Further, there is no coloring such as yellowing of the paint and the coating film and the color of the base material can be reflected as it is. It is a paint.

Claims (1)

(57) [Claims] 1. A water-soluble or water-dispersible matte comprising an acrylic polymer, a water-miscible organic solvent in which the polymer is soluble, an aluminum alcoholate represented by the formula (1), an amino resin, an alkaline substance and water. Electrodeposition paint. Embedded image Al (OR ¹ ) _m (OR ² ) _3-m (1) (where R ¹ represents an alkyl group or alkenyl group having 5 to 36 carbon atoms, or an aryl group, and R ¹ is the same or different. R ² represents an alkyl group having 4 or less carbon atoms, and R ² may be the same or different.
≦ m ≦ 3. )